Vibroacoustic analysis of panels using a wave and finite element method

This thesis concerns extending a wave and finite element (WFE) method to predict the vibroacoustic characteristics of structures, including wave propagation characteristics, sound transmission loss and sound radiation, of flat infinite and finite panels and infinite cylinders. In this method, a coupled fluid/structure system is considered. A segment of the structure is modelled using a conventional finite element (FE) method. The fluid spaces are modelled analytically. The fluid pressures on the surfaces of the segment exert external nodal forces on the FE model of the structure. Periodicity theory and equilibrium conditions are then used to postprocess the mass and stiffness matrices of the periodic cell together with the nodal forces. The spectral dynamic stiffnesses of the fluids and structure are developed and assembled into the total spectral dynamic stiffness matrix of the coupled system. This is then used to calculate the structural response to excitation. The excitations can be acoustic pressures or general structural excitation. Once the structural displacements are found, the acoustic pressures can be calculated analytically. The WFE method is also used to develop homogenised models of honeycomb cored panels, with the model size being reduced by Guyan reduction. This method is applied to infinite panels, finite panels and cylindrical shells. For simple structures analytical methods are available. The WFE predictions show excellent agreement with analytical solutions. For complicated structures (e.g., laminated panels, honeycomb-cored panels, and composite cylindrical shells), analytical solutions are difficult. Due to the use of the FE method, the geometry of arbitrarily complex structures can be captured straightforwardly. The full power of commercial FE packages and element libraries can be utilised. It is straightforward and efficient to use the WFE method, which provides accurate predictions at low computational cost.

Name thesis:degree_name

PhD

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor dc:publisher

ResearchSpace@Auckland

Year dc:date.issued

2018

Author dc:creator

• Yang, Yi

Advisor dc:contributor.advisor

• Mace, B

Statement dc:rights

• Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher.

Licence dc:rights.uri

• https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm

Handle dc:identifier.uri

https://hdl.handle.net/2292/45214

OAI identifier oai:identifier

oai:researchspace.auckland.ac.nz:2292/45214